Treatment of felts



United States Patent 3,022,199 TREATMENT OF FELTS William G. Lloyd, Bay City, and Turner Alfrey, Jr., Midland, Mich., assignors to The Dow Chemical Company, Midland, Mich., a corporation of Delaware No Drawing. Filed Nov. 12, 1959, Ser. No, 852,163 8 Claims. (Cl. 117-141) This invention relates to a treatment for felts. It more particularly relates to a process for conferring dimensional stability upon felts by treating these with a dilute aqueous solution of a degradable hydrophilic polymer having the following general formula:

where R, is selected from the group consisting of hydrogen and lower alkyl containing from 1 to about 6 carbon atoms; X is a member of the group consisting of (A) an organic sulfur containing radical derived from a compound of the group consisting of (a) aliphatic sulfides of the formula, R SR wherein R and R each represent a member of the group consisting of (1) alkyl radicals containing from 1 to 6 carbon atoms, (2) haloalkyl radicals containing from 1 to 6 carbon atoms, (3) hydroxyalkyl radicals containing from 1 to 6 carbon atoms, (4) aralkyl radicals containing from 7 to 12 carbon atoms, (5) (CH CH O) CH CH OI-I wherein m is an integer from 1 to 5, (6) C,,H COOH,

metal, (9) C H CONH C nHiu C nHZn-H (l1) C H COC H and (12) --'C H CN, wherein n in substituents (6), (7), (8), (9), (10), (11) and 12) is an integer from 1 to 5 with the total number of carbon atoms in each of substituents (6), (7), (8), (9), (10), (11) and (12) not exceeding 6, and where the total number of carbon atoms of the R and R groups attached to a common sulfur atom does not exceed 18, and (b) a heterocyclic sulfur containing radical derived from a compound of the group consisting of tetrahydrothiophene, hydroxysubstituted tetrahydrothiophene, halosubstituted tetrahydrothiophene, alkylsubstituted tetrahydrothiophene where alkyl is limited to those groups conatining from 1 to 5 carbon atoms, thiac'jclohexane and p-oxathiane, and (B) a heterocyclic nitrogen radical derived from a compound of the group consisting of pyridine, quinoline and isoquinoline and nucleus alkylated homologs and analogs thereof; Y is a common anionic radical such as halogen, carbonate and the like; and Z is an integer greater than 10.

Felts in general undergo shrinkage when subjected to wetting. This undesirable phenomenon is particularly noticeable in wool and wool-rayon felts, which when wetted, exhibit relatively poor dimensional stability and undergo extensive shrinkage. This shrinkage problem now unexpectedly has been overcome by the method of this invention wherein carded felt masses (batts) are moistened with a dilute aqueous solution of certain hydrophilic vinylaromatic based polymers before subjecting the batts to the pressure of an oscillating roller, in the presence of heat, to produce the final felting action. Alternatively, finished felts can be treated with the polymer solutions and these so-treated felts dried under convditions where the polymer degrades to leave on the fibers of the felts a resinous hydrophobic coating.

{ar-vinylbenzyl] sulfonium chloride).

3,922,199 Patented Feb. 20, 1962 It is the principal object of this invention, therefore, to provide a treatment for felts to render such felts dimensionally stable when wetted. An advantage of this process is that dilute treatment solutions can be used which make this process economically favorable. Another advantage of the invention is that this treatment is very simple to apply either directly during preparation of the felts, or to the finished felts. Still other objects and advantages will be recognized by one skilled in the art from the method description which follows.

To illustrate this invention, a sample of a Wool or wool-rayon felt is spread taut in a frame, and then immersed of a short period of time in a dilute aqueous solution containing from about 0.02 to about 2 percent of a water soluble ar-vinylbenzyl polymer having one of the X and one of the Y functional groups described heretofore. By the term solution is meant a substantially transparent liquid in which no suspended particles are visible to the human eye under ordinary light. This period of immersion is not critical; a minimum treatment time of at least about 10 seconds is sufficient, although longer times may be employed if desired.

As the solution treated felt is removed from the solution and dried at room temperature or higher (ordinarily from about 70 to about centigrade), the labile group (X group defined heretofore) of the hydrophilic polymer degrades, depositing a resinous hydrophobic residue upon the individual felt fibers.

Although quite dilute solutions, 0.4 percent or less polymer by weight, are efiective in imparting to felts the desired wet dimensional stability, aqueous solutions containing up to 2 percent or more of the hydrophilic polymer can be prepared without a corresponding detrimental increase in the treatment solution viscosity. Additionally, if desired, solutions containing high concentramethanol-water, acetone-water, butanol-water, isopropanel-water and the like.

The degree of protection given to the felts by use of the more concentrated solutions is not appreciably better than that shown by treatment in the more dilute polymeric solutions, but with the concentrated solutions there can be achieved a change in the hand of the felts. The materials can take on a stiffer, harder texture, if concentrated treatment solutions are used.

Ordinarily, in carrying out the method of the invention, a plain solution of the polymer is used. However, if desired, alternatively, surfactants or wetting agents can be added to the polymeric solutions to further promote the pickup of the polymer by the felt fibers.

The method of this invention can be illustrated further by the following examples, but is not meant to be limited thereto.

EXAMPLE 1 A 7 inch square of a medium weight (21 mg./cm. nndyed, white, 50 percent wool-5O percent rayon felt was placed in a pair of 6 inch steel embroidery hoops in such a manner that the felt was held taut. The transverse axis (comparable to selvage to selvage or Woof axis in woven fabrics) was marked on the sample. The soheld feit sample then was immersed for about 30 seconds in a 0.04 percent aqueous solution of poly(dimethyl After this time the sample was removed from the solution, dried for about three hours at room temperature, and then heated for about 30 minutes at about 100-105 centigrade under an absolute pressure of about 5 millimeters.

The poly(dimethyl [ar-vinylbenzyl] sulfonium chloride) was prepared by agitating an aqueous suspension pf poly(ar-vinylbenzyl chloride) latex with about a 10 or more, to prepare the gel-like product.

Example/4', was treated 'witha 1.0 percent-aqueous solu- 3 perature for an extended period of time, about 4 days Portions of this gel were diluted with water to obtain the various aqueous solutions used for treating the felts. The dried, treated felt sample then was removed from the hoops,

and a'rectangular patch of about 80 mm. to a side was cut from the center. This patch was measured on all four sides and was then subjected to the following test schedule. The patch was immersed for about 60 seconds in deionized water at. about 28 to about 32 centigrade with gentle agitation, then removed-from the Water, and measured wet for immediate dimensional change. The wet sample then was dried at room temperature by placing it in a path of moving air from an electrician for 6 hours and re-measured to determine the shrinkage upon drying. Finally, the sample was immersed in boiling deionized water for about 120 seconds, removed, partially dried at room temperature and then finished dried for one hour at about 80 under reduced pressure as above.

4 chloride) and then tested for shrinkage using the same procedure as in Example 1. Results of this test are recorded in Table I.

EXAMPLE *6 EXAMPLE 7 A medium-weight, black, dyed, all-wool felt sample, as described in Example 6, was treated with a 1.0 percent aqueous solutionof the poly-(dimethyl [ar-vinylbenzyl] sulfonium chloride) and then tested for shrinkage using the same general procedures as in Example 1.

' Results of this test are recorded in Table I.

Table I i DIMENSIONAL STABILITY OF WOOL AND WOOL-RAYON IE ELIS TREATED WITH POLY(DIMETHYL[AR VINYLBENZYIJSULFONIULI CHLORIDE) 'Percent Shrinkage Soln Wet-Room Temp. Room Temp. 11 0+ Boiled in H 0 and Test N o. Concn, Felt H Air Dried Dried Percent V Transverse Longltu- Transverse Longitu- Transverse V Longitudinal dinal dinal 1 Control percent wool-50 18. 8 2. 2 21. 1 4. 3 V 26. 1 8. 6

percent rayon. 0.04 do 5. 5 0. 5 14. 6 2. 8 23. 8 8. 0 1.7 ml 6.9 1. 5 17.3 6.4 nil nil 1. 1 0. 5 5. 1 2. 4

Control--. All-wool, medium, 4. 9 1. 1 14. 8 3. 4 26. 8 6. 9

undyed felt. 6 0.20 "do 2. 3 0. 5 10.2 2. 2 21. 1 5. 8 7 1.0 do nil nil 1. 7 nil 7.0 1. 6 8 Control-.- All-wool, medium, 4. 9 1. 4 10. 9 3. 8 21. 9 7. 4

- blackdyed felt. 9 0.04 do 2. 6 0. 5 8. 5 2. 8 1 9. 5 6. 9 10 1.0 do 0.6 nil 2.3 0.6 8.7 2.6

EXAMPLE 8 After this last severe test, the sample was given final measurements for shrinkage, all of the shrinkage data being recordedin the following Table I. For purpose of comparison, samples of felt not treated with poly (dimethyl [ar-vinylbenzyl] sulfonium chloride) were tested by the same procedure, Results of these tests also are recorded in Table I.

EXAMPLE 2 EXAMPLE 3 A similar wool-rayon felt sample was treated with a 1.0 percent aqueous solution of the poly(dimethyl [arvinylbenzyl] sulfonium chloride) and then tested for "shrinkageusing the same procedure as in Example 1. Results of this test are recorded in Table I.

EXAMPLE 4 A medium-heavy (32 mg./cm. white, undyed all- [wool felt was treated with a 0.2 percent aqueous solutio'nflof the poly(dimethyl [ar-vinylbenzyl] sulfonium chloride) and thentested forshrinkage using the same procedure as in Example 1.

recorded in Table I.- V V EXAMPLE 5 I A medium-heavy all-wool felt sample, as describedf A sample of the 50 percent wool-50 percent rayon felt was treated with a 1 percent aqueous solution of poly(4- [ar-vinylbenzyl] oxathianium chloride) and then tested for shrinkage at room temperature by the same pro- Results of this test are cedure as described in Example -1.1 Results of this test are recorded in Table II. The poly(4-[ar-vinylbenzyl] oxathianium chloride) was prepared by agitating at room temperature for about 4 days a mixture of poly(ar-vinylbenzyl chloride) latex and a 10 percent molar excess of p-oxathiane to yield a gel-like polymeric'product. Portions of this gel were dilutedwith water to prepare the dilute aqueous solution used in treating the felt.

EXAMPLE 9 A sample of the 50 percent wool-50 percent rayon felt 7 EXAMPLE 10 A sample of the 50 percent wool-50 percent rayon felt was treated with a '1 percent aqueous solution of poly (di-Z-hydroxyethyl [ar-vinylbenzyl] sulfonium chloride), this polymer being prepared by solution polymerization of the product obtained by reacting vinylben'zyl chloride monomerwith diethanol sulfide, and the so-treated felt tion or the poly(dimethyl [ai' vinylbenzyl] sulfonium then was tested for shrinkage at'room' temperature using the procedure described in Example 7. Results of this test are recorded in Table H.

Table 11 DIMENSIONAL STABILITY OF 50 PERCENT WOOL-50 PERCENT RAYON FELT TREATED (VITH VARIOUS HYDROPHILIC DEGRADABLE POLYMERS Percent Shrinkage Soln Wet-Room Temp, H1O Room Temp. H O-l-Air Test No. Treatment SlutionP0lymer Concn, Dried Percent Transverse Longi- Transverse Long-ltudinal tudinal 1 Control 18.8 2.2 21.1 4.3 2 Poly(4-arvinylbenzy11-oxathianium chloride 1.0 1.0 0. 5 3. 2 1. 7 3 Poly(1-[ar-vinylhenzyl]-pyridinium chloride 1. 0 9. 0 1. 2 l3. 2 3. 9 4 Poly(di-2-hydroxyethyl[ar]vinylbensyl]sullonium chloride 1i 0 nil nil 1. 4 0.6

In a manner similar to that described in the foregoing examples, dimensional stability is imparted to felts by treatment with dilute aqueous solutions of ar-vinylbenzyl polymers having pendant functional groups chosen from the following radicals, -quinolinium, -2,4-lutidinium, o-picolinium, m-picolinium, p-picolinium, -isoquinolinium, and -4(w-hydroxypropyl)-pyridinium and the like, which polymers are prepared by reacting poly- (ar-vinylbenzyDchloride latex with the corresponding heterocyclic compound at room temperature according to the method reported in Example 8.

Additionally, the (ar-vinylbenzyl)sulfonium chloride polymers can have pendant functional substituted sulfonium groups as shown in the following examples; -2- hydroxyethyl ethyl sulfonium, -benzyl methyl sulfonium, -2-hydroxyethyl carboxymethyl sulfonium, -2hydroxyethyl carboxymethyl sodium salt sulfonium, -methyl polymethylene oxide sulfonium, -methyl Z-hydroxyethyl sulfonium, -di-2-carboxyethyl sulfonium, -methyl carbamidomethyl sulfonium, -methyl carbarnidoethyl sulfonium, -2-hydroxyethyl carbamidoethyl sulfonium, -2,3-dihydroxypropyl methyl sulfonium, -methyl Z-hydroxy-Z- carboxyethyl sodium salt sulfoniurn, di-Z-carbm'doethyl sulfonium, -hexyl acetonitrile sulfonium, -carboxyamyl potassium salt methyl sulfoniuu -butyl carboxymethyl potassium salt methyl sulfonium, -butyl carboxymethyl ethoxyethyl sulfonium, -2-chlorohexyl 2-oxopropane sulfonium, -carbamidoamyl bromoroethyl sulfonium, -amylnitn'le ethyl sulfonium, -2-hydroxyhexyl methyl sul fonium, -4-amylbenzyl iodomethyl sulfonium, -butoxyethyl carbamidopropyl suifonium, and 3-oxohexyl methyl sulfonium. The sulfur containing functional group also can be -tetrahydrothiophene, hydroxy substituted tetrahydrothiophene, chlorotetrahydrothiophene, B-amyltetrahydrothiophene, 3-methyltetrahydrothiophene and tetrahydrothiapyran. The above listed poly-(ar-vinylbenzyi)- sulfonium chlorides and the poly-(ar-vinylbenzwl)tetrahydrothiophenium chlorides and the poly(ar-vinylbenzyl)hexahydrothiapyrylium chloride are prepared by reacting, at temperatures ranging from about 18 to about 100 C., ar-vinylbenzyl chloride with the corresponding organic sulfur containing compound to prepare the corresponding vinylbenzyl sulfonium chloride, vinylbenzyl thiophenium chloride and vinylbenzyl hexahydrothiapyrylium monomer, and polymerizing an aqueous solution of the monomer by conventional vinyl polymerization techniques to make the corresponding water soluble poly(ar-vinylbenzyl)sulfonium chloride or the poly-arvinylbenzyl) tetrahydrothiophenium chloride.

Various modifications can be made in the present invention without departing from the spirit or scope thereof for it is understoodthat we limit ourselves only as defined in the appended claims.

felts which comprises; treating said felts with a dilute aqueous solution of a degradable hydrophilic polymer having the general formula where R is selected from the group consisting of hydrogen and alkyl containing 1 to about 6 carbon atoms, X is a member of the group consisting of (A) an organic sulfur containing radical derived from a compound of the group consisting of (a) aliphatic sulfides of the formula, R SR wherein R and R each represents a member of the group consisting of (1) alkyl radicals containing from 1 to 6 carbon atoms, (2) haloalkyl radicals containing from 1 to 6 carbon atoms, (3) hydroxyalkyl radicals containing from 1 to 6 carbon atoms, (4) aralkyl radicals containing from 7 to 12 carbon atoms, (5) (CH CH O) CH CH OH wherein m is an integer from 1 t0 5, (6) -C,,H COOH, (7) --C H COOC l-I (8) C,,H COO alkali metal, (9) 2n H2 11) -C H COC,,I-i and (12) C H CN, Wherein n in substituents (6), (7), (8), (9'), (10), (1i) and (12) is an integer from 1 to 5 with the total number of carbon atoms in each of substituents (6), (7), (8), (9), (10), (ll) and (12) not exceeding 6, and where the total number of carbon atoms of the R and R groups attached to a common sulfur atom does not exceed 18 and (b) a heterocyclic sulfur containing radical derived from a compound of the group consisting of tetrahydrothiophene, hydroxy substituted tetrahydrothiophene, halo-substituted tetrahydrothiophene, alkyl substituted tetrahydrothiophene where alkyl is limited to those groups containing from 1 to 5 carbon atoms, thiacyclohexane and p-oxathiane, and (B) a heterocyclic nitrogen radical derived from a compound of the group consisting of pyridine, quinoline and isoquinoline and nucleus alkylated homologs and analogs thereof; Y is a common anionic radical such as halogen, carbonate and the like; and Z is an integer greater than 10.

2. The process of claim 1 wherein the aqueous solution of the (ar-vinylbenzyDbased polymer contains from about 0.02 to about 2 percent polymer by weight.

3. A process for conferring dimensional stability on wool and wool-rayon felts which comprises; treating said felts with an aqueous solution containing from about 0.04 to about 1.0 percent of poly(dirnethyl ar-viny1- benzyl snlfoniurn chloride), and drying the so-treated felts at temperatures from about 70 to about 100 centigrade thereby to degrade said polymer and leave a resinous hydrophobic coating upon said felts.

4. A process for conferringtdimensional stability on wool and wool-rayon felts which comprises; treating said felts with an aqueous solution containing from about 0.04

to about 1.0 percent of poly(di-2-hydroxyethyl [at-vinylbenzyl] sulfoniuin chioride) and drying the so-treated felts at temperatures from about 70 to about 100 centigrade thereby to degrade said polymer and leave a resinous by- I drophobic coating upon said felts.

5. A process for conferring dimensional stability on 3 title) and drying the so-treated felts at about 100 centigrade to degrade said polymer and leave a resinous hydrophobic coating upon said felts.

7. A process for conferring dimensional stability on W001 and Wool-rayon felts which comprises; treating said felts with an aqueous solution containing about 1.0 percent of poly-(di-Z-hydroxyethyl [ar-vinylbenzyl} sulfonium chloride) and drying the so-treated felts at about 100 centigrade thereby to degrade said'polymer and leave a resinous hydrophobic coating upon said felts.

8. A process for conferring dimensional stability on wool and Wool-rayon felts which comprises; treating said felts with an aqueous solution containing about 1.0 percent of poly(4-[ar-vinylbenzyl] oxathianium chloride) and drying the se-treated felts at about 100 Centigrade thereby to degrade said polymer and leave a resinous hy drophobic coating upon said felts;

References Cited in the file of this patent UNITED STATES PATENTS 2,884,057 Wilson et a1 Apr. 28, 1959 2,895,925 Hwa July 21, 1959 2,941,696 Price -c June 21, 1960 

1. A PROCESS FOR CONFERRING DIMENSIONAL STABILITY UPON FELTS WHICH COMPRISES; TREATING SAID FELTS WITH A DILUTE AQUEOUS SOLUTION OF A DEGRADABLE HYDROPHILIC POLYMER HAVING THE GENERAL FORMULA 